Diaphragm pump and method for contactless actuation thereof

ABSTRACT

Depicted and described herein is a diaphragm pump (1) for conveying a gaseous and/or liquid medium, having at least one deformable membrane (2) for changing the size of a work chamber (3) of the diaphragm pump (1), and having at least one actuating unit (4) for deforming the membrane (2) by means of applying contact-free force to the membrane (2) using a magnetic field, wherein the membrane (2) comprises and/or consists of a material which is magnetic and/or magnetizable, and the actuating unit (4) features at least one magnetic and/or magnetizable actuating means (7). According to the invention, the actuating unit (4) is rotatably mounted and the membrane (2) is arranged circumferentially with respect to the actuating unit (4), wherein, in a dead point position of the membrane (2), the polarization direction of the magnetic field generated between the material of the membrane (2) and the actuating means (7) is oriented in a direction radial to the axis of rotation of the actuating unit (4).

The present invention relates to a diaphragm pump for conveying agaseous and/or liquid medium, having at least one deformable membranefor changing the size of a work chamber of the diaphragm pump, andhaving at least one actuating unit for deforming the membrane by meansof applying contact-free force to the membrane using a magnetic field,wherein the membrane comprises and/or consists of a material which ismagnetic and/or magnetizable, and the actuating unit features at leastone magnetic and/or magnetizable actuating means. A magnetic field,which causes the membrane to deform, is generated between the materialof the membrane and the actuating means.

The present invention furthermore relates to a method for thecontact-free actuation of the membranes in multiple work spaces of adiaphragm pump in order to convey a gaseous and/or liquid medium.

Diaphragm pumps usually feature at least one work chamber, which isbordered by a deformable membrane (for changing the size of the workchamber) and a wall, in which is formed at least one inlet and at leastone outlet for a medium, which is drawn into the expanding work chamberthrough the inlet during a suction phase and is discharged from theshrinking work chamber through the outlet during a compression phase. Acontrollable actuating unit or drive unit is provided for deforming themembrane.

It is proposed in DE 1 184 447 A1 to use a connecting rod as theactuating unit. The free end of the connecting rod is affixed to themembrane via an associated mounting disc. The other end of theconnecting rod is eccentrically mounted on a crankshaft such that,during operation of a diaphragm pump of this kind, a stroke movement ofthe membrane results which is oriented in an approximately perpendiculardirection. The disadvantage of this diaphragm pump is that the membraneis subjected to a permanent clamping load between the connecting rod andthe mounting disc, which causes a high degree of wear on the membrane.

An alternative drive concept follows from EP 0 604 740 A1. Proposed inthis case is the deformation of a single membrane by means of applyingcontact-free force using a magnetic field. For this purpose, the side ofthe membrane facing away from the work chamber is designed to bemagnetically reactive. The membrane is deformed by means of a rotatingdisc, upon which permanent magnets are arranged. By rotating the disc,or rather the permanent magnets arranged thereupon, a cyclic magneticfield surrounding a central axis of the membrane acts on the membrane,thus conveying the fluid to be conveyed in a rotating movement from theinlet to the outlet. A cyclic work chamber is thus formed, whichsurrounds the central axis of the membrane and into which the fluid tobe conveyed is drawn through an inlet, then conveyed around the centralaxis, and ultimately expelled through an outlet.

The disadvantage of this concept is that, due to the cyclically rotatingmagnetic field, the membrane is subjected to a wave-like movement thatresults in strong and widespread deformation, which is associated withsignificant material wear and/or costly maintenance. Moreover, thisrotational conveying movement is relatively inefficient.

Among other areas, diaphragm pumps are used in the fields of medicaland/or analytical and/or environmental technology, for example inanesthesiology devices or gas sensors. The use of diaphragm pumps asprecision pumps normally requires a compact design, particularly whenthe diaphragm pumps being used are integrated as sub-assemblies intocorresponding medical and/or analysis devices. Furthermore, a highdegree of long-term stability is essential.

Moreover, it is in particular preferable for applications in medicaltechnology and gas analysis to operate in a low-pulsation manner. Inthis context, the term “pulsation” is understood to mean a sinusoidalconveying curve which can be traced back to the periodic change involume of the work chamber, or rather to the deformation of themembrane. The pressure pulses or pressure peaks associated withpulsation can cause damage to sensitive sensor instruments or distortmeasurement results.

Finally, it is desirable for diaphragm pumps used in a laboratory and/ora patient environment to operate quietly.

The object of the present invention is to provide a diaphragm pump, inparticular for use in the field of gas analysis and/or medicaltechnology, which is characterized by having a compact design andoperating in a wear-resistant, quiet and/or low-pulsation manner, inparticular a pulsation-free manner, while also conveying at a highvolume. At the same time, the diaphragm pump according to the inventionis intended to fulfill additional specific requirements such as a highdegree of long-term stability, cost consciousness, and/or valve sealing.The object of the invention is to furthermore provide a method forcontact-free actuation of the membranes in multiple work chambers of adiaphragm pump that allows for the construction of a diaphragm pumphaving the aforementioned advantages.

The present invention will be achieved by means of a diaphragm pumphaving the features of claims 1, 3, 8, 9, and 10 as well as by means ofa method having the features of claim 11. Preferential embodiments arethe subject-matter of the dependent claims.

The invention makes it possible to design the diaphragm pump to operatein a low-pulsation or even a largely pulsation-free manner and/or in awear-resistant and/or quiet manner along with having a compact designand a small number of parts. It is possible for fewer wear points to berealized in comparison to vane cell pumps and eccentric diaphragm pumps,which leads to longer service life and/or reduced maintenance outlay. Inparticular, a high conveying capacity can be achieved in comparison to,for example, eccentric diaphragm pumps, and significantly higher endpressures and greater pressure stability can be achieved in comparisonto, for example, vane cell pumps. Further advantages of the diaphragmpump according to the invention may in particular be reduced sensitivityto moisture and/or particulate matter in comparison to vane cell pumpsas well as system and valve sealing that is comparable to conventionalpumps, eccentric diaphragm pumps in particular. Using the diaphragm pumpaccording to the invention, it is furthermore possible to achieve aspecific conveying pressure or conveying volume at a lower rotationalspeed in comparison to vane cell pumps in particular, which may beassociated with a longer motor lifespan and improved pumpcontrollability. Finally, an internal pressure or vacuum restriction canbe implemented by means of adjusting the magnetic forces, as a result ofwhich motor or system protection is possible without additionalelectronic measures.

Consequently, as an alternative to or in relation to the prior art, theinvention proposes refined (drive) concepts used to deform at least onemembrane of a diaphragm pump by means of applying contact-free force tothe membrane using a magnetic field, as a result of which the advantagesdescribed above in particular are able to be realized.

According to first embodiment of the present invention, it is providedthat the actuating unit is rotatably mounted and the membrane isarranged circumferentially with respect to the actuating unit, whereby,in a dead point position of the membrane, the polarization direction ofthe magnetic field generated between the material of the membrane andthe actuating means is oriented in a direction radial to the axis ofrotation of the actuating unit. In a membrane dead point position, thedistance between the actuating means and the membrane preferably reachesan extreme. Moreover, in this position, the greatest attractive or thegreatest repulsive magnetic force between the actuating means and themembrane material is reached, in which case the (main) polarizationdirection of the magnetic field acting between the membrane and theactuating means is oriented in a direction essentially transverse orradial to the axis of rotation of the actuating unit.

In the context of the present invention, the term “(main) polarizationdirection of the magnetic field” is understood to mean the directionvector between magnetic poles of opposite polarity which are beinggenerated by the membrane material on the one hand and the actuatingmeans on the other.

The circumferential arrangement of the membrane with respect to theactuating unit enables the diaphragm pump according to the invention tohave a very space-efficient design. In particular, a work chamber of thediaphragm pump can be arranged axially within the longitudinal dimensionof the actuating unit, the result of which is a very compact design forthe diaphragm pump according to the invention. According to theinvention, rotation of the actuating unit generates a cyclicallyrotating magnetic field and a membrane pumping movement that is solelylinear, which leads to significantly less material wear in contrast tothe wave-like deformation of the membrane known from EP 0 604 740 A1,thus ensuring a high degree of long-term stability and valve sealing.

The term “membrane dead point position” may include both an “outer deadpoint position” and an “inner dead point position.” A membrane deadpoint position is then reached when the actuating unit reaches aspecific rotational position where a magnetic pole of the actuating unitis preferably located directly opposite a magnetic pole of the membrane.In the outer dead point position, the distance between the magneticmaterial of the membrane on the one hand and the actuating means on theother is at a minimum. In this case, the attraction, or ratherdeformation, of the membrane in the direction of the actuating means isat a maximum. Correspondingly, the inner dead point position isunderstood to mean a condition in which the distance between themagnetic material of the membrane on the one hand and the actuatingmeans on the other is at a maximum. In this case, the repulsion, orrather deformation, of the membrane away from the actuating means is ata maximum.

Between the two dead center positions, the membrane can assume a restingposition where little or no magnetic force is acting on the membrane.According to the invention, the (main) polarization direction, or ratherthe direction vector between poles of opposite polarity, runs in adirection transverse—hence radial—to the axis of rotation of theactuating unit. In this context, the membrane is preferably locateddirectly opposite the actuating means in a dead point position.

The actuating means can be supported on a radial circumferential surfaceof the actuating unit and/or at least portions thereof insertedcircumferentially into the actuating unit. The actuating means can inthis case form at least part of the circumferential surface of theactuating unit.

In order to ensure that the membrane is deformed enough for pumpmovement by means of applying contact-free force to the membrane using amagnetic field, the surface normal in the central area of the membraneworking surface can be oriented in a direction perpendicular or ratherradial to the axis of rotation of the actuating unit.

There may be provided two work chambers, four work chambers, or aninteger multiple of two work chambers, in which case each work chamberis preferably associated with a separate pump head. The work spaces arein particular arranged circumferentially with respect to the actuatingunit and offset with respect to one another in the direction of rotationof the actuating unit. This approach also enables a compact arrangementof multiple work chambers, in particular axially within the longitudinaldimension of the actuating unit. In this case, the work chambers arepreferably distributed uniformly across the circumference of theactuating unit, the result of which is a small design volume for thepump according to the invention. The rotary movement of a commonactuating unit then actuates the membranes of multiple work chambersconsecutively, which results in a small number of components for thediaphragm pump and simpler pump assembly overall.

Along with the membrane, the work chamber is also bordered by a pumphead of the pump, which features at least one inlet, through which themedium to be conveyed is drawn into the work chamber during a suctionphase. Also provided is at least one outlet, through which the medium tobe conveyed is removed from the shrinking work chamber during acompression phase. Maintenance outlay is reduced through the use ofmultiple separate pump heads, thereby enabling, for example, thereplacement when necessary of defective membranes by means of detachingthe respective pump head.

The actuating unit can have one or multiple actuating means. Eachactuating means can be comprised of one or multiple permanent magnets.For example, a diametrically magnetized ring magnet can be provided asan actuating means. The actuating unit preferably then features, in thedirection of rotation, two magnetic poles located opposite one anotherand of opposite polarization. Alternatively, an actuating means can alsobe comprised of a group of permanent magnets having the same outwardpolarization. The use of disc or bar magnets is preferable in this case.

According to a second, alternative embodiment of the present invention,the actuating unit is rotatably mounted and the membrane is arranged atthe front of the actuating unit, which is in particular disc-shaped orplate-shaped, whereby, in a dead point position, the (main) polarizationdirection of the magnetic field generated between the material of themembrane and the actuating means is oriented essentially in thedirection of the rotational axis of the actuating unit or parallelthereto, and wherein an axis of rotation of the actuating unit is offsetlaterally, and preferably parallel to, a membrane central axis on themembrane such that, upon rotation of the actuating unit, the actuatingmeans moves cyclically past the membrane and cyclically crosses over themembrane. The actuating means preferably moves along a circular path tomove past the membrane.

By cyclically crossing over the membrane, a magnetic field is generatedbetween the actuating means and the membrane, thus causing the cyclicdeformation of the membrane. In this context, the actuating means sweepsin particular across the area of the central axis of the membrane. Inaddition, the maximum deflection of the membrane during the suctionphase or the compression phase exists in a central area of the membranesurface, or rather in the area of the central axis of the membrane. Thisallows for effective and non-damaging pump operation.

In this second embodiment, it is preferably provided that the membranesof multiple work chambers of the diaphragm pump are consecutivelydeformed by means of rotating the common actuating unit. This in turnallows the diaphragm pump according to the invention to have a verycompact design along with a small number of individual components. Withrespect to the central axis thereof, each membrane is arranged at adistance from the axis of rotation of the actuating unit such that, uponrotation of the actuating unit, at least one actuating means movescyclically and consecutively past each membrane or rather crosses overit. In doing so, each membrane (preferably the area of the central axisthereof) is consecutively deflected to a maximum and deformed in thedirection of the rotational axis or parallel to the rotational axis ofthe actuating unit. In this context, the surface normal in the centralarea of a working surface of the membrane is preferably oriented in thedirection of the rotational axis of the actuating unit or ratherparallel thereto.

In terms of structure, it is preferable for the actuating means to besupported on an axial front side of the actuating unit and/or at leastportions thereof inserted into an axial front side of the actuatingunit.

The actuating unit in this embodiment of the invention is preferably ofdisc-shaped design and features a frontally arranged and/or insertedactuating means. Further preferably, multiple actuating means areprovided, in which case each actuating means can be comprised of a groupof disc or bar magnets, and the magnets of a group have the same outwardpolarization. Doing so ensures optimal contact-free actuation of themembranes.

Multiple, preferably four, membranes with associated work chambers canbe provided, in which case the work chambers are arranged opposite anaxial front side of the actuating unit and opposite the actuating means.Doing so achieves an effective magnetic interaction between themembranes and the actuating unit.

It is advantageous for multiple work chambers to be associated with acommon pump head. In this particular case, the pump head features atleast one collecting chamber for merging the parallel inlets and/oroutlets from the work chambers. This allows for a structurally simpleand compact design of the diaphragm pump according to the invention.

The actuating unit in this embodiment can also feature one or multipleactuating means. Each actuating means can be comprised of one ormultiple permanent magnets. Preferably, an actuating means is comprisedof a group of permanent magnets having the same outward polarization.The use of disc or bar magnets is preferable in this case.

The following statements may be implemented in both of the conceptsdescribed above for deforming a membrane by means of applyingcontact-free force to the membrane using a magnetic field without thisfact being expressly mentioned hereinafter.

The actuating unit preferably features multiple outer magnetic poles ofnumber n having opposite polarization and acting on the membrane.Alternatively, the actuating unit can feature multiple magnetic polegroups of number n having opposite polarization, whereby each magneticpole group consists only of outer magnetic poles having the samepolarization, and whereby n is greater than or equal to two. Themagnetic poles or magnetic pole groups of opposite polarization arepreferably arranged successively in the direction of rotation of theactuating unit, whereby the magnetic pole or magnetic pole groups can bearranged successively at an offset of 360°/n to one another in thedirection of rotation of the actuating unit. The membrane likewisefeatures an outer magnetic pole oriented with respect to the actuatingunit or, optionally, also a group of outer magnetic poles having thesame polarization. Upon rotation of the actuating unit, the membrane canthus be moved alternatingly into the outer dead point position and intothe inner dead point position.

In the context of the present invention, the term “magnetic pole” ispreferably understood to mean a circumferential or front facing outerarea of the actuating unit, in the vicinity of which the magnetic fieldis particularly strong since this is where the field lines of themagnetic field emerge or enter. The direction vector of the magneticfield is thus generated between the magnetic poles of the actuating unitand the membrane. In the alternative embodiments proposed according tothe invention, the direction vector can either run radially (or rathertransversely or axially) in the direction of or parallel to the axis ofrotation of the actuating unit.

In a diaphragm pump having multiple work chambers which areconsecutively arranged in the actuating unit direction of rotation, themembranes on the actuator side can form identical or identically namedmagnetic poles. This can be achieved, for example, by the magnetic meansin the membranes having the same orientation. By means of rotating thecommon actuating unit, the membranes that are consecutively arranged inmultiple work chambers can then be moved consecutively and cyclicallyinto the inner or the outer dead point position. A directed suction orpressure flow through work chambers within the diaphragm pump incommunication with one another is thus ensured. Alternatively, it isalso possible for the membranes of two work chambers on the side of theactuating unit and preferably offset with respect to one another by 180°to form different or differently named magnetic poles.

Preferably, the actuating means of the actuating unit and/or themagnetic means of the membrane is a permanent magnet. A particularlystrong magnetic interaction between the actuating means and the membraneis ensured in this way. The actuating means can, for example, be adiametrically magnetized ring magnet. The north pole is then located onone half of the ring magnet, and the south pole is on the other half.The ring magnet can be mounted on a magnet carrier of the actuatingmeans and rotatably arranged around an axis of rotation extending in anaxial direction through the ring magnet. The actuating means can also bea bar magnet or a disc magnet. An actuating means can also be formed bya group of bar-shaped or disc-shaped permanent magnets. For example, theactuating unit can feature two groups of bar or disc magnets arranged atan offset of preferably 180° to one another in the actuating unitdirection of rotation. The magnets of a group are preferably oriented inthe same direction such that the actuating unit features onlyidentically named magnetic poles in the portion of the group on themembrane side.

Further preferably, provided in the direction of rotation between themagnetic poles or magnetic pole groups are outer regions of theactuating unit which are more weakly magnetized or not magnetized. Inparticular, the actuating unit can feature at least two, and preferablyonly two, non-magnetic outer regions which are arranged in particular atan offset to one another at regular intervals in the actuating unitdirection of rotation, and further preferably arranged at an offset of180° to one another in the actuating unit direction of rotation. In thisway, magnetic poles or magnetic pole groups arranged in the actuatingunit direction of rotation—hence magnetic regions—alternate withnon-magnetic or only weakly magnetic regions. Therefore, upon rotationof the actuating unit, the membrane can alternately move into an outerdead point position when a magnetic pole of opposite polarization islocated opposite the membrane, or move into an inner dead point positionwhen a magnetic pole of the same polarization is located opposite themembrane. In contrast, if a region that is non-magnetic or only weaklymagnetic is located opposite the membrane, then the membrane preferablyassumes a resting position located between the two dead point positions.

In particular, multiple work chambers can be present which are arrangedeither circumferentially with respect to or at the front of theactuating unit. Each work chamber is associated with a membrane. Thenumber m of work chambers is preferably greater than or equal to thenumber of actuating means of the actuating unit. The work chambers canin particular be arranged at an offset of 360°/m to one another in theactuating unit direction of rotation. In doing so, the magnetic means ofall membranes can be oriented in the same direction such that theactuator sides of the membranes feature only magnetic poles theorientation of which is identically named or identically polar. However,as an alternative, a counter-polar orientation of the magnetic poles ofmembranes arranged consecutively in the actuating unit direction ofrotation is also possible. This will be addressed in detail furtherbelow.

Particularly preferably, it is intended by means of the polarization ofthe outer magnetic poles of the actuating unit on the one hand and thepolarization of the outer magnetic poles of the membrane on the otherhand as well as, optionally, by means of non-magnetic or only weaklymagnetic regions between the outer magnetic poles of the actuating unitthat no rotational position of the actuating unit will result in themembranes of all work chambers of the pump being simultaneously situatedat an equal inner or outer dead point, or result in all of them beingsimultaneously situated in an equal (preferably non-deflected) positionbetween the dead points. Very low-pulsation operation is made possiblethereby.

In a certain rotational position of the actuating unit, in which themembranes of preferably two work chambers are situated in a preferablynon-deformed or weakly deformed position between the dead points, andwhich is reached during a suction phase or a compression phase, at leastthe membrane of a third work chamber can then be situated at an innerdead point position, and at least the membrane of a fourth work chambercan be situated at an outer dead point position. The inner dead pointposition can characterize the beginning of the suction phase, and theouter dead point position can characterize the beginning of thecompression phase.

Moreover, it can be advantageous if, in a certain rotational position ofthe actuating unit, the number of membranes situated in the restingposition conforms with the total number of membranes situated in aninner or outer dead point position.

For example, the actuating unit can feature two outer magnetic poles orouter magnetic pole groups arranged at an offset of 180° to one anotherand having opposite polarization, and four work chambers can be providedwhich are each arranged at an offset of 90° to one another in theactuating unit direction of rotation. Preferably on a side facing theactuating unit, the work chambers feature outer magnetic poles havingthe same polarization. The result thereby is that, in a certainrotational position of the actuating unit, the membranes of two workchambers preferably located opposite one another are situated in anon-deformed or weakly deformed position between the dead points, whilstthe membrane of a third work chamber reaches an outer dead pointposition, and the membrane of a fourth work chamber, which is preferablylocated opposite the third work chamber, reaches an inner dead pointposition. Low-pulsation or pulsation-free operation of the diaphragmpump is achieved as a result.

In order to further improve the compact design of the diaphragm pumpaccording to the invention, at least one common inlet collecting chamberand/or at least one common outlet collecting chamber can be provided,said chambers being in fluidic communication with one another via theinlets and outlets, respectively, of the work chambers. As a result, theinlet and outlet flows of each work chamber are fluidically merged, thussimplifying the structural design of the diaphragm pump and enabling thefluid flows being drawn in and discharged to be equalized. Thecollecting chambers are designed in particular to merge the inlets oroutlets of the respective work chambers in parallel. As a result,external merging of the inlets or outlets of the work chambers outsidethe diaphragm pump is not necessary. This allows for easy integration ofthe diaphragm pump according to the invention into parent equipment suchas medical and/or (gas) analysis devices.

According to a further alternative embodiment of the invention, at leasttwo work chambers are arranged at an offset of 160° to 200°, preferably180°, to one another in the direction of rotation of the actuating unit,whereby the membranes of the work chambers on the actuator side featuredifferent magnetic poles or magnetic pole groups, and wherein theactuating unit on the membrane side features at least two differentmagnetic poles or magnetic pole groups arranged at an offset of 160° to200°, preferably 180°, to one another in the direction of rotation ofthe actuating unit. In a certain rotational position of the actuatingunit, where the magnetic poles of the membranes interact with themagnetic poles of the actuating unit, the membranes of the two workchambers located opposite are then either simultaneously attracted tothe actuating unit or simultaneously repelled by the actuating unit.

In other words, at no rotational position of the actuating unit is acondition reached in which the membrane of a work chamber is situated inan inner dead point position, and the membrane of a second work chamberlocated opposite is in an outer dead point position. Both of themembranes located opposite are situated in either the inner dead pointposition or the outer dead point position. This has the result of themagnetic forces and/or moments acting on the actuating unit during pumpoperation cancelling each other out, thus reducing the mechanical loadon the actuating unit. The use of cost-effective components is thus madepossible. In addition, combining the embodiment of the inventiondescribed above with the embodiments of the invention described evenearlier is feasible and advantageous.

Preferably, n pairings of work chambers are provided, whereby eachpairing features two work chambers arranged at an offset of 160° to200°, preferably 180°, to one another in the actuating unit direction ofrotation, or rather arranged opposite, the membrane poles of which areopposite to one another on the actuating unit side.

According to a further alternative embodiment of the present invention,it is provided that the actuating unit is rotatably mounted, and astator unit is provided for generating a rotating magnetic field,whereby the rotating magnetic field generated by the stator unit isdesigned to drive the actuating unit in a rotary manner. Particularlypreferably, the stator unit is designed to be plate-shaped and/orimplemented to complement the embodiments described above.

As a result, driving the actuating unit via the stator unit allows forfurther reduction in the physical volume occupied by the diaphragm pumpsince the stator unit is able to be designed to have a significantlylower volume than conventional drive devices such as electric motors.

In the context of this embodiment of the invention, the drive for theactuating unit acts in particular according to the principle of abrushless DC motor. In this case, the actuating unit is ultimatelyacting as a rotor driven by means of the rotating magnetic field, whichis generated by means of the stator unit. The stator unit features coilsfor generating the rotating magnetic field. By means of suitablecircuitry, these coils are controlled or commutated with respect to oneanother so as to generate a rotating magnetic field, as a result ofwhich the actuating unit is pulled or rather driven in the direction ofrotation.

It may be preferable for the actuating means in this embodiment inparticular to be shaped like a segment of a ring. Doing so ensuresoptimal interaction in particular with the stator unit, resulting in ahigh degree of efficiency for the diaphragm pump according to theinvention.

Preferably, the actuating means is an integral part of the actuatingunit, in which case the geometry of the actuating unit on thecircumferential side and/or the front side can be complemented by theactuating means in order to become disc-shaped. The actuating means canbe flush mounted, in particular glued, into a complementary recess onthe front side and/or circumferential side of the actuating unit. Acompact design can be achieved in this way, thus enabling optimal actionby or interaction between both the actuating unit and the stator unit.

Particularly preferably, the actuating means generates, on an exteriorside of the actuating unit facing a work chamber, a magnetic pole foracting on a membrane, and, on an exterior side located opposite andfacing the stator unit, generates a magnetic pole of preferably oppositepolarization for interacting with the stator unit in the rotatingmagnetic field. In this case, the actuating unit can preferably featuremagnetic poles on two front sides located opposite in the direction ofthe rotational axis and preferably having opposite polarization, as aresult of which two functions are fulfilled: First, the actuating unitenters into interaction via the one front side with the rotatingmagnetic field, as a result of which the rotary drive of the actuatingunit is accomplished. Second, at the same time and via the oppositefront side, the magnetic action on the at least one membrane isrealized, as a result of which the pumping or suction action is ensured.

The distance between the actuating means and the magnetic means of themembrane can be adjustable, in particular in an axial direction, theimplementation of which is easy in embodiments of the invention inparticular where the actuating unit and the work chamber or rathermembrane are arranged in the direction of the rotational axis, or ratherone after the other in an axial direction. It is possible in this caseto vary the width of the air gap between the actuating means and themagnetic material of the membrane as necessary by means of adjusting theposition of the work chamber and/or the position of the actuating unitin relation to one another in an axial direction, thus influencing thestrength of the magnetic coupling between the membrane and the actuatingmeans. This aspect of the invention has proprietary inventivesignificance.

According to a further alternative embodiment of the present invention,it is provided that, in spatial terms, the work chamber is providedbetween the membrane and the actuating means. The work chamber isbordered on one side by the membrane and on the other side by a housingportion of the pump. In this embodiment of the invention, direct contactbetween the membrane and the actuating means is prevented at every deadpoint position of the membrane. If, however, the membrane were to borderdirectly on the actuating means, it would in an outer dead pointposition of the membrane be possible for the membrane and the actuatingmeans to touch, which is associated with undesirable and cyclicallyrecurring noise. This problem is overcome and quiet operation ensured bymeans of the arrangement according to the invention of the work chamberbetween the membrane and the actuating means.

Structurally, a housing portion of the pump, which borders along thework chamber and the actuating means, is located between the membraneand the actuating means. The housing portion can have a smaller wallthickness where it borders the actuating means and/or can consist of amaterial such that contact-free deformation of the membrane is possibleusing the magnetic field generated between the membrane and theactuating means and passing through the housing portion. It isadvantageous for the magnetic field to be only minimally influenced bythe housing portion such that deformation of the membrane is possible bymeans of applying contact-free force using the magnetic field.

In order to achieve the object stated in the introductory section, it isproposed according to the method that the membranes be deformed in acontact-free manner by at least two, preferably four, work chambers bymeans of force applied using a magnetic field, whereby the magneticfield is generated between the membranes and at least one magneticand/or magnetizable actuating means of a rotatable actuating unit, andwherein membranes arranged successively in direction of rotation of theactuating unit are deformed in a contact-free manner by means ofmagnetic interaction with the actuating means.

It is understood that the features of the various embodiments of theinvention described above as well as described and shown hereinafter inreference to the drawings may be combined with one another as necessary,even if this fact is not explicitly mentioned in detail. Individualfeatures may be used in isolation from other features described or shownin order to further embody the invention. The paragraph format selecteddoes not preclude a combination of features from various paragraphs.

The invention will be explained hereinafter in connection with thedrawings and in reference to preferential embodiments. Shown are:

FIG. 1 a perspective view of a diaphragm pump according to the inventionas specified by a first embodiment,

FIG. 2 a cross-sectional view of the diaphragm pump from FIG. 1 alongthe section line II-II,

FIG. 3 an exploded perspective depiction of a diaphragm pump accordingto the invention as specified by a second embodiment,

FIG. 4 a further exploded perspective depiction of the diaphragm pumpaccording to the invention from FIG. 3,

FIG. 5 a cross-sectional view of the diaphragm pump from FIG. 3 alongthe section line V-V from FIG. 4,

FIG. 6 an exploded perspective depiction of a diaphragm pump accordingto the invention as specified by a third embodiment,

FIG. 7 a cross-sectional view of the diaphragm pump from FIG. 6,

FIG. 8 a perspective view of a diaphragm pump according to the inventionas specified by a further embodiment,

FIG. 9 a first cross-sectional view of the diaphragm pump from FIG. 8along the section line IX-IX,

FIG. 10 a second additional cross-sectional view of the diaphragm pumpfrom FIG. 8 along the section line X-X, and

FIG. 11 an exploded perspective view of the diaphragm pump from FIG. 8.

FIGS. 1 and 2 show a diaphragm pump 1 for conveying a gaseous and/orliquid medium (not depicted). The diaphragm pump 1 has multiple (four inthe example depicted) deformable diaphragms 2 for changing the size offour work chambers 3 of the diaphragm pump 1.

A pumping process consists of a suction phase and a compression phase,with the medium being drawn into an expanding work chamber 3 during thesuction phase and then discharged from a shrinking work chamber 3 duringa compression or pressure phase. In this context, the membranes 2 forenlarging or shrinking the size of the work chamber 3 are at leastpartially deformable, in particular elastic.

The diaphragm pump 1 features an actuating unit 4, which is rotatablymounted or driven, to deform the membranes 2 (see FIG. 2). A drivedevice 5, preferably an electric motor, is provided to drive theactuating unit 4. The deformation of the membranes 2 takes place bymeans of applying contact-free force using a magnetic field, whereby themembranes 2 comprise or consist of a material which is magnetic ormagnetizable. In the example depicted, each membrane 2 features apermanent magnet as a magnetic means 6, which is embedded into oraccommodated in a central area of the membrane 2. In this context, themagnetic means 6 of all membranes 2 preferably have the same polarity asthe actuating unit 4.

In the example depicted, the actuating unit 4 features only oneactuating means 7, which is designed as a diametrically magnetized ringmagnet with two magnetic poles of opposite polarization. In thisrespect, the actuating unit 4 features a receiving portion 4 a, whichspans circumferentially and in which the actuating means 7 isaccommodated and supported. The actuating unit 4 can in particular be ofmulti-piece design in order to allow the actuating means 7 to slide ontothe receiving portion 4 a. In particular, the actuating unit 4 consistsof two components able to be screwed or inserted together, each of whichfeatures a radial projection and between which the actuating means 7 issupported in an axial direction on the receiving portion 4 a. However,other design solutions are also possible.

In order to deform the membranes 2 in a contact-free manner, a magneticfield (not depicted), which is oriented in a direction radial to an axisof rotation 8 of the actuating unit 4, is generated between theactuating means 7 on the one hand and the magnetic means 6 of theassociated membrane 2 on the other.

The actuating unit 4 in the embodiment depicted in FIG. 2 is designed tobe sleeve-shaped or wave-shaped.

In the embodiment depicted, the two outer magnetic poles of theactuating means 7 are arranged at an offset of 180° to one another inthe actuating unit 4 direction of rotation, and the four work chambers 3are arranged at an offset of 90° to one another in the direction ofrotation of the actuating unit 4.

As is evident from FIG. 2 in particular, the membranes 2 having theassociated work chambers 3 are arranged within the longitudinaldimension of the actuating unit 4.

Shown in FIG. 2 is a rotational position of the actuating unit 4 wherethe membranes 2 of two work chambers 3 located opposite aresimultaneously deformed due to the magnetic field. In this context, themembrane 2 of a first, upper work chamber 3 (shown in FIG. 2) isrepelled by the south pole S of the actuating means, or rather ringmagnets, and pushed into an inner dead point position (not shown),whilst the membrane 2 of a second, lower work chamber 3 (shown in FIG.2) is attracted by the north pole N of the ring magnet, or ratheractuating means 7, and pushed into an outer dead point position (notshown). The magnetically repelled membrane 2 and the magneticallyattracted membrane 2 are arranged at an offset of 180° to one another inthe direction of rotation of the actuating unit 4. The membranes 2 ofthe two other work chambers 3 are in this rotational position of theactuating unit 4 subject to at most a small magnetic interaction withthe actuating unit 7 and are situated in a non-deformed restingposition. This is due to the fact that the magnetic means 6 of thismembrane 2 in the rotational position of the actuating unit 4 shown (seeFIG. 4, Regions 7 c) are located opposite regions which are designed tobe non-magnetic or only weakly magnetic. Accordingly, no magneticinteraction or at most a small magnetic interaction takes place betweenthe magnetic means 6 and these regions of the actuating unit 4.

Upon rotation of the actuating unit 4 (as per FIG. 2), the membranes 2of the work chambers 3 consecutively arranged in the direction ofrotation of the actuating unit 4 are consecutively actuated in acontact-free manner by means of the moving magnetic poles of theactuating unit 4. Preferably, no rotational position of the actuatingunit 4 will result in the membranes 2 of all work chambers 3 beingsimultaneously situated at an equal inner or outer dead point, or resultin all of them being simultaneously situated at an equal non-deflectedor weakly deflected position between the dead points. For example, at acertain rotational position of the actuating unit 4, only the membrane 2of a first work chamber 3 can be situated in an inner dead pointposition, only the membrane 2 of a second work chamber 3 can be situatedin an outer dead point position, and the membranes 2 of a further workchamber 3 can be situated in a preferably non-deflected or only slightlydeflected position between the dead points, which is reached during thesuction phase or the compression phase. Very low-pulsation operation ofthe diaphragm pump 1 according to the invention is made possible in thisway. The course of movement of the membranes 2 lends itself todescription as a sine curve, in which context the course of movement ofthe membranes 2 of the four work chambers 3 can be described as foursine curves offset in opposition to one another, while the courses ofmovement of the membranes 2 overlap. As a consequence, the membranemovement cycle can be rendered in idealized fashion as a sine curve.

As is not shown, the two membranes 2 (depicted at the left and right ofFIG. 2) located opposite in relation to the outer side facing theactuating unit 4 can also have the opposite polarity as one another orfeature different magnetic poles. As a result of this, upon rotationalmovement of the actuating unit 4, the membranes 2 of both work chamberslocated opposite are pushed into either an inner dead point position orinto an outer dead point position by means of the magnetic poles of theactuating unit 4. This can have the result of the magnetic forces and/ormoments acting on the actuating unit 4 cancelling each other out suchthat the mechanical load on the actuating unit 4 is accordingly reduced.

In the embodiment depicted, a separate pump head 9 is provided for eachmembrane 2. The pump heads 9 are correspondingly arranged at an offsetof 90° to one another in the direction of rotation of the actuating unit4. The pump heads 9 each feature an inner housing portion 10 and anouter housing portion 11. Formed in the inner housing portion 10 is achamber wall 12, the top of which borders the corresponding work chamber3.

The diaphragm pump 1 features an actuator housing 13 for accommodatingthe actuating unit 4. The pump heads 9 are screwed onto the actuatorhousing 13, whereby the edge portion of the membranes 2 can be fixed toform a seal between the actuator housing 13 on the one hand and the pumpheads 9 on the other.

Each pump head 9 can feature valves (see FIG. 5), preferably non-returnvalves, in order to prevent the medium from being discharged through aninlet during the compression phase or being drawn in through an outletduring the suction phase (see FIG. 4, Inlet 17, Outlet 18).

The drive apparatus 5 is also screwed onto the actuator housing 13. Thedrive apparatus 5 features a flange plate 14 for this purpose. Theactuating unit 4 is non-rotatably arranged on a driving shaft 15 of thedrive apparatus 5.

Arranged on each chamber wall 12 are at least one inlet and at least oneoutlet (see FIG. 4, Inlet 17, Outlet 18). The medium is drawn into thework chamber 3 through the inlet during the suction phase and expelledfrom the work chamber 3 through the outlet during the compression phase.

The medium to be conveyed is drawn into the diaphragm pump 1 through asuction line 19. The medium is led through the suction line 19 and intoan inlet collecting chamber 20, whereupon the medium is fed from theinlet collecting chamber 20 to the inlets of the respective workchambers 3. Furthermore provided is an outlet collecting chamber 21,where the medium expelled from the work chambers 3 through the outletsis collected and accommodated before leaving the diaphragm pump 1through a pressure line 22. In the example depicted, the inletcollecting chamber 20 and the outlet collecting chamber 21 are arrangedat the front of the actuating unit 4 and opposite the drive apparatus 5.The inlet collecting chamber 20 and the outlet collecting chamber 21 areformed by a preferably multi-piece collecting housing 23, with aseparate housing portion being provided for each collecting chamber 20,21. The collecting housing 23 is screwed onto the actuator housing 13.The drive apparatus 5, the actuator housing 13, and the collectinghousing 23 are located one after the other in the direction of the axisof rotation 8 of the actuating unit 4, thus resulting in a compactdesign.

Alternative embodiments of diaphragm pumps 1 are depicted in FIGS. 3 to11. Components of the diaphragm pumps having the same function aredescribed using the same reference signs.

It is evident from FIGS. 3 to 5 that a drive apparatus 5, an actuatorhousing 13, and a pump head 9 are in this embodiment arranged axiallyone after the other in the direction of the axis of rotation 8 of anactuating unit 4, and they are screwed together.

The pump head 9, the actuator housing 13, and the flange plate 14feature an identical outer contour. In particular—apart from fluid orelectrical connections—no components are provided which project beyondthis outer contour. This enables the diaphragm pump 1 to have a compactand, in particular, flat design.

The actuating unit 4 in this embodiment is designed as a rotating discor to be plate-shaped, in which case the actuator housing 13 features acorresponding disc-shaped recess 24, in which the actuating unit 4 isaccommodated (see FIG. 4).

In the embodiment depicted, a common pump head 9 is provided for allfour work chambers 3. The pump head 9 features a cover 25, whichfeatures the suction line 19 and the pressure line 22 (see FIG. 3). Thepump head 9 furthermore features an inner housing portion 10 and anouter housing portion 11. Each work chamber 3 is bordered by a chamberwall 12 of the inner housing portion 10 and by a membrane 2. Eachmembrane 2 features a magnetic means 6.

The actuating unit 4 as per FIG. 4 features, inserted on the front side,two actuating means 7, which are each formed by a group of permanentmagnets 7 a, 7 b having the same outward polarization. The actuatingmeans 7, or rather the permanent magnets 7 a, 7 b arranged in groupfashion, are arranged at an offset of 180° to one another in thedirection of rotation of the actuating unit 4. Regions 7 c, which aredesigned to be non-magnetic or at most weakly magnetic, are providedbetween the permanent magnets 7 a, 7 b in a circumferential direction orrather the direction of rotation of the actuating unit 4.

The front side of the actuating unit 4 facing the drive apparatus 5otherwise features a bore 26 corresponding to a driving shaft 15 of thedrive apparatus 5. The actuating unit 4 is non-rotatably connected tothe driving shaft 15. Moreover, a circular depression 27 foraccommodating a circular projection 16 of the drive apparatus 5 isprovided on said front side of the actuating unit 4. Reliable mountingof the actuating unit 4 is ensured in this way.

As is evident from FIG. 5, an inlet collecting chamber 20 and an outletcollecting chamber 21 are formed by the outer housing portion 11 of thepump head 9. The collecting chambers 20, 21 are closed on the top by thecover 25 of the pump head 9.

The pump head 9 features valves 28 (only hinted at in the depiction), inparticular non-return valves. The medium is thereby prevented from beingexpelled through an inlet 17 during the compression phase and beingdrawn in through an outlet 18 during the suction phase. The valves 28are preferably arranged between the inner housing portion 10 and theouter housing portion 11.

As is also evident from FIG. 5, the membranes 2 having the associatedwork chambers 3 are arranged (immediately) opposite a front side of theactuating unit 4. The membranes 2 are essentially arranged on a commonplane. Shown in FIG. 5 is a rotational position of the actuating unit 4where the membranes 2 of two work chambers 3 arranged at an offset of180° to one another in the direction of rotation of the actuating unit 4are simultaneously deformed due to the existing magnetic field.

The central axes M of the membranes 2 run at a lateral offset to theaxis of rotation 8 of the actuating unit 4. The magnetic means 6 of themembranes 2 are in this case centrally arranged in the area of themembrane axis M. Upon rotation of the actuating unit 4, the actuatingmeans 7 of the actuating unit 4 are led along a circular path past themagnetic means 6 of the membranes 2, which causes the cylic deflectionof the membranes 2.

As per FIG. 5, the membrane 2 of a first work chamber 3 (depicted atleft in FIG. 5) is repelled by the south pole of a permanent magnet 7 aof the first actuating means 7 and pushed into an inner dead pointposition (not shown), whilst the membrane of a second work chamber 3(depicted at right in FIG. 5) is attracted by the north pole of apermanent magnet 7 b of the second actuating means 7 and pushed into anouter dead point position (not shown). In order to achievepulsation-free operation of the diaphragm pump 1, it is provided that,in said rotational position of the actuating unit 4, the membranes 2 ofthe two other work chambers 3 are subject to a slight magneticinteraction since, in the rotational position of the actuating unit 4shown, they are arranged opposite regions 7 c designed to benon-magnetic or at most weakly magnetic.

The magnetic means 6 of two membranes 2 arranged at an offset of 180° toone another in the direction of rotation of the actuating unit 4 orrather located opposite (such as the magnetic means 6 of the membranes 2depicted at left and right in FIG. 5), can also differ from FIG. 5 onthe actuator side and have opposite polarity or differently namedmagnetic poles. In this case, the magnetic means 6 are arranged suchthat the membrane 2 of a work chamber 3 features a south pole on theside (externally) of the actuating unit 4, and the membrane 2 of theopposite work chamber 3 features a north pole on the side of theactuating unit 4. At a certain rotational position of the actuating unit4, the membranes 2 located opposite are then simultaneously attracted tothe actuating unit 4 or repelled by the actuating unit 4 or, rather, themembranes 2 located opposite are simultaneously situated at an innerdead point position or an outer dead point position. The result therebycan be that the magnetic forces on both sides of the actuating unit 4axis of rotation 8 acting on the actuating unit 4 can be balanced, thusreaching a torque equilibrium. Imbalances which can lead to vibrationsand increased wear can thus be avoided.

A further, alternative embodiment of a diaphragm pump will be describedhereinafter in reference to FIGS. 6 and 7. As is not depicted, a pumphead is provided which, together with four membranes 2 fixed between thepump head and an actuator housing 13, forms four work chambers. Thedesign of the pump head can correspond to the embodiment shown in FIGS.3 to 5.

In this embodiment, a drive apparatus 5 for an actuating unit 4 isprovided which is designed as a plate-shaped stator unit 29 having aplurality of coils 30. The coils 30 are preferably arranged in thestator unit 29 concentrically and offset at regular intervals from oneanother in the direction of rotation of the actuating unit 4. Thediaphragm pump 1 features control electronics (not shown) designed forcontrolling the polarity changes of the coils 30. The rotationalposition of the actuating unit 4 is detected thereby, in which case thechange in polarity of the coils 30 used to generate a rotating magneticfield depends on said rotational position. The driving of or rotation ofthe actuating unit 4 then takes place as a result of the rotatingmagnetic field generated by the coils 30.

The stator unit 29 is preferably designed for rotatably mounting theactuating unit 4. A bearing bore 31, preferably centrally arranged, isprovided for this purpose. Accordingly, the actuating unit 4 features acentrally arranged bearing journal 32, which is in particular able tofit precisely into the bearing bore 31. The stator unit 29 is connectedto an actuator housing 13.

The embodiment depicted furthermore provides two actuating means 7,which are each in the form of axially magnetized permanent magnetshaving the circular shape of a segment of a ring. The actuating means 7are arranged at an offset of 180° to one another in the direction ofrotation of the actuating unit 4 and preferably extend across 90° in thedirection of rotation of the actuating unit 4. Doing so enables aneffective magnetic interaction with the stator unit 29 and a high degreeof efficiency for the diaphragm pump 1.

The actuating means 7 are an integral part of the actuating unit 4 andcomplement it circumferentially and on the front side to form a discshape, as is particularly clear from FIG. 6. On a front side of theactuating unit 4 facing away from the drive unit 5, the actuating means7 each generate a magnetic pole N, S for acting on the membrane 2located opposite, as well as a magnetic pole N, S of oppositepolarization on the other front side of the actuating unit 4 forinteracting with the stator unit 29. Referring to FIG. 7, it is also thecase in this embodiment that the membranes 2 are arranged opposite thefront side of the actuating unit 4 and are essentially horizontallyarranged on a common plane.

In order to enable low-pulsation operation of the diaphragm pump 1, themembrane 2 of a work chamber (arranged at left in FIG. 7) is, in acertain rotational position of the actuating unit 4 (shown in FIG. 7),attracted by the north pole N of the first actuating means 7, which hasthe shape of a segment of a ring, and pushed into an outer dead pointposition (not shown), whilst the membrane 2 of a work chamber (arrangedat right in FIG. 7) is repelled by the south pole S of the secondactuating means 7, which has the shape of a segment of a ring, andpushed into an inner dead point position (not shown). In a certainrotational position of the actuating unit, the magnetically repelledmembrane 2 and the magnetically attracted membrane 2 are arranged at anoffset of 180° to one another. In said certain rotational position, themembranes 2 of two further work chambers are associated withnon-magnetized or at most weakly magnetized regions 7 c and are thussituated in a non-deformed position between the dead point positions.Similar to the previous embodiments, at no point in time, hence at norotational position of the actuating unit 4, will the membranes 2 of allwork chambers be simultaneously situated at an equal inner or outer deadpoint position, or at an equal—preferably non-deflected or weaklydeflected—position between the dead point positions. At said certainrotational position of the actuating unit 4, preferably only themembrane 2 of a first work chamber is situated in the inner dead pointposition, only the membrane 2 of a second work chamber is situated inthe outer dead point position, and the membranes 2 of two further workchambers can be situated in a preferably non-deformed or only slightlydeformed position, which is reached during the suction phase or thecompression phase and lies between the dead point positions.Corresponding advantages are able to be realized in this way.

Another alternative embodiment of the diaphragm pump 1 will be describedin reference to FIGS. 8 to 11. Not shown is a drive apparatus fordriving the actuating unit 4. According to the embodiments previouslydescribed, the drive apparatus can be designed as an electric motor oras a brushless DC motor.

As is evident from FIG. 8, the diaphragm pump 1 features an actuatorhousing 13, an inner housing portion 10, as well as an outer housingportion 11. With respect to an axis of rotation 8 of the actuating unit4 (FIG. 9), the actuator housing 13, the inner housing portion 10, aswell as the outer housing portion 11 are arranged one after the other inan axial direction, and they are screwed together. The drive apparatusis preferably secured to the actuator housing 13. The actuator housing13 features for this purpose corresponding connecting means, inparticular threaded and/or receiving bores (schematically indicated inFIG. 8). In particular, the actuator housing 13 features a throughgoingbore 13 a, through which a driving shaft of the drive apparatus can beinserted in order to drive the actuating unit 4.

The actuator housing 13, the inner housing portion 10, and the outerhousing portion 11 feature an outer contour that is very nearlycomplementary and corresponding, in particular rectangular or square.

In the embodiment depicted, four separate pump heads 9 are provided,each of which is arranged and secured on an outer side of the housing ofthe diaphragm pump 1. Each pump head 9 has a suction line 19 and apressure line 22, with the fluid to be conveyed being drawn into thepump head 9 through the suction line 19 and conveyed out of the pumphead 9 through the pressure line 22.

The membranes 2 are fixed edgewise between the inner housing portion 10and the outer housing portion 11 (see FIG. 9). The actuating unit 4 isdesigned as a rotating disc in this embodiment as well. Each membrane 2furthermore features a magnetic means 6, for example in the form of apermanent magnet. Each work chamber 3 is bordered by both a chamber wall12 and the membrane 2, in which case the chamber wall 12 is formed by anarea of the inner housing portion 10. The actuating unit 4 featuresactuating means 7, which are designed as permanent magnets 7 a, 7 barranged in group fashion (as per FIG. 4). The unequal magnetic poles orrather magnetic pole groups generated on the membrane side by thepermanent magnets 7 a, 7 b are arranged at an offset of 180° to oneanother in the direction of rotation of the actuating unit 4. As shownfor the embodiment in FIG. 4, regions that are designed to benon-magnetic or at most weakly magnetic are provided between thepermanent magnets 7 a, 7 b in a circumferential direction or rather thedirection of rotation of the actuating unit 4.

The work chambers 3 are arranged between the membranes 2 and thepermanent magnets 7 a, 7 b of the actuating unit 4. In terms ofstructure, the membranes 2 are separated from the actuating unit 4 andthus from the actuating means 7 by the chamber walls 12 of the innerhousing portion 10. At least in the area of the chamber walls 12, theinner housing portion 10 consists of a material, for example a plasticmaterial, which does not resist the magnetic coupling between theactuating means 7 and the magnetic means 6 of the membrane 2 and permitscontact-free deformation of the membranes 2 by the actuating means 7.

In all of the embodiments shown and described, the membranes 2 canfeature a round, preferably circular, outer contour. The magnetic means6, which are preferably cylindrical, are arranged and supported in acentral area of the membranes 2 or in the area of the central axes M. Inorder to prevent contact between the magnetic means 6 and a fluid beingconveyed, the magnetic means 6 can be arranged on a side of the membrane2 facing away from the work chamber 3. For this purpose, the centralareas of the membranes 2 can be designed with added thickness incomparison to the edge areas thereof, in which case the membranes can bedesigned to have depressions or receiving portions for the magneticmeans 6. The magnetic means 6 are then mounted on the membranes 2 bymeans of sliding the magnetic means 6 into the receiving portions and,optionally, by means of gluing.

The embodiment shown in FIGS. 8 to 11 is advantageous in that contactbetween the actuating means 7 of the actuating unit 4 and the magneticmeans 6 of the membranes 2 during operation of the diaphragm pump 1 isreliably precluded. This results in a significant reduction of unwantednoise during operation of the diaphragm pump 1.

It should be noted that the edge areas of the membranes 2 are preferablydesigned to have thin walls in order to enable easy deformability.Preferably, only the edge areas of the membranes 2 are deformed duringpump operation, whereas the central areas—which are strengthened by therigid magnetic means 6—retain essentially the same shape.

The pump heads 9 are connected to the sides of the work chambers 3 in alateral direction (see FIG. 10). Each pump head 9 features a baseplate33 and a head portion 34. The suction line 19 and the pressure line 22are formed by the head portion 34. The baseplate 33 is arranged on, inparticular screwed onto, the actuator housing 13 and the outer housingportion 11. Valves 28 in the form of an inlet valve 35 and an outletvalve 36 are provided between the baseplate 33 and the head portion 34(see FIG. 11).

During pump operation, the fluid to be conveyed is drawn in through thesuction line 19 of a pump head 9 during the suction phase. After passingthrough the inlet valve 35, the fluid continues into the work chamber 3via the inner housing portion 10. The fluid is likewise expelled fromthe work chamber 3 via the inner housing portion 10 during thecompression phase.

It is further evident from FIG. 11 that the actuating unit 4 features aplurality of preferably cylindrical recesses 37, which are arrangedconsecutively in the direction of rotation and into which the magnets 7a, 7 b are inserted.

It is understood that the previously described embodiments are notlimited to the design of the diaphragm pump 1 having four work chambers3. Moreover, the features of the previously described embodiments may becombined with one another as necessary, even if this fact is notexplicitly described or shown in detail.

List of reference signs:  1 Diaphragm pump  2 Membrane  3 Work chamber 4 Actuating unit  4a Receiving portion  5 Drive apparatus  6 Magneticmeans  7 Actuating means  7a Magnet  7b Magnet  7c Region  8 Axis ofrotation  9 Pump head 10 Housing portion 11 Housing portion 12 Chamberwall 13 Actuator housing 13a Throughgoing bore 14 Flange plate 15Driving shaft 16 Projection 17 Inlet 18 Outlet 19 Suction line 20 Inletcollecting chamber 21 Outlet collecting chamber 22 Pressure line 23Collecting housing 24 Recess 25 Cover 26 Bore 27 Depression 28 Valve 29Stator unit 30 Coil 31 Bearing bore 32 Bearing journal 33 Baseplate 34Head portion 35 Inlet valve 36 Outlet valve 37 Recess

1-11. (canceled)
 12. A diaphragm pump for conveying a gaseous, liquid,or gaseous/liquid medium, comprising: at least one deformable membranefor changing the size of a work chamber of the diaphragm pump; and atleast one actuating unit for deforming the membrane by applyingcontact-free force to the membrane using a magnetic field, wherein themembrane comprises or consists of a material which is magnetic ormagnetizable, and the at least one actuating unit includes at least onemagnetic or magnetizable actuating means.
 13. The diaphragm pump ofclaim 12, wherein the actuating unit is rotatably mounted and themembrane is arranged circumferentially with respect to the actuatingunit; and wherein, in a dead point position of the membrane, thepolarization direction of the magnetic field generated between thematerial of the membrane and the actuating means is oriented in adirection radial to the axis of rotation of the actuating unit.
 14. Thediaphragm pump of claim 12, wherein an axis of rotation of the actuatingunit is arranged at an offset and parallel to a membrane central axis onthe membrane such that, upon rotation of the actuating unit, theactuating means moves cyclically past the membrane and cyclicallycrosses over the membrane.
 15. The diaphragm pump according to claim 12,wherein the actuating unit includes multiple magnetic poles of number(n) having opposite polarization and acting on the membrane; and whereineach magnetic pole group consists only of magnetic poles having the samepolarization, and wherein (n) is greater than or equal to two and themagnetic poles are generated by means of one or multiple actuatingmeans.
 16. The diaphragm pump according to claim 15, wherein themagnetic poles or magnetic pole groups of the actuating unit havingopposite polarization are arranged successively in the direction ofrotation of the actuating unit, wherein the magnetic poles or magneticpole groups are arranged at an offset of 360°/n to one another in thedirection of rotation of the actuating unit.
 17. The diaphragm pumpaccording to claim 15, wherein multiple work chambers of number (m) areprovided, wherein each work chamber is associated with a membrane,wherein (m) is preferably greater than or equal to (n), and wherein thework chambers are arranged at an offset of 360°/m to one another in thedirection of rotation of the actuating unit.
 18. The diaphragm pump ofclaim 12, wherein a magnetic field is generated between the material ofthe membrane and the actuating means, wherein the actuating unit isrotatably mounted, and a stator unit is provided for generating arotating magnetic field, wherein the rotating magnetic field generatedby the stator unit is designed to drive the actuating unit in a rotarymanner.
 19. The diaphragm pump of claim 12, wherein a magnetic field isgenerated between the material of the membrane and the actuating means,and wherein the work chamber is arranged between the actuating means andthe membrane.
 20. The diaphragm pump according to claim 12, wherein atleast two work chambers are provided, wherein each work chamber isassociated with a separate pump head.
 21. The diaphragm pump accordingto claim 20, wherein the at least one deformable membrane comprisemultiple membranes arranged successively in the direction of rotation ofthe actuating unit that are able to be deformed in a contact-free mannerusing the actuating means; and wherein at least two work chambers of thediaphragm pump are associated with a common pump head.
 22. The diaphragmpump of claim 20, wherein a magnetic field is generated between thematerial of the membrane and the actuating means, wherein the at leasttwo work chambers are arranged at an offset of 160° to 200° to oneanother in the direction of rotation of the actuating unit, wherein themembranes of the work chambers on the actuator side feature differentmagnetic poles, and wherein the actuating unit on the membrane sideincludes at least two different magnetic poles arranged at an offset of160° to 200° to one another in the direction of rotation of theactuating unit.
 23. A method for applying contact-free force to themembranes of the work chambers of a diaphragm pump used for conveying agaseous, liquid, or liquid/gaseous comprising a diaphragm pump of claim20, wherein the membranes of the at least two work chambers are deformedfree of contact by means of force applied using a magnetic field,wherein the magnetic field is generated between the membranes and atleast one magnetic or magnetizable actuating means of a rotatableactuating unit, and wherein membranes arranged successively in thedirection of rotation of the actuating unit are deformed in acontact-free manner by means of magnetic interaction with the actuatingmeans.